Ubuntu Linux (amd64/x86_64 only)
To install the launcher for Ubuntu (and other similar Debian-based distributions), you can paste the following into a console, and enter your password when prompted. This will add the RuneScape apt repository to your computer so that you will be informed of updates to the launcher when they happen.
sudo -s -- << EOF
wget -O - https://content.runescape.com/downloads/ubuntu/runescape.gpg.key | apt-key add -
mkdir -p /etc/apt/sources.list.d
echo "deb https://content.runescape.com/downloads/ubuntu trusty non-free" > /etc/apt/sources.list.d/runescape.list
apt-get install -y runescape-launcher